Utility giant Severn Trent received fewer customer complaints in the last quarter, despite seeing more supply interruptions than usual.

Britain’s biggest listed water company said a 12% year-on-year reduction in water quality complaints coincided with “more supply interruptions than normal”, as Severn Trent revealed it is set to pocket at least £50 million in outperformance payments this year.

Performance payments are doled out by water regulator Ofwat to companies that are delivering a good service for customers.

Severn Trent also revealed that while its gender pay gap, which stands at 2.4%, has further to go, it is making “strong progress” in supporting workplace diversity, gender pay equality and social mobility.

Severn Trent, which provides water across the Midlands, also confirmed that it is on track to meet market expectations for the year following positive momentum in its waste division.

The FTSE 100 firm’s shares were up more than 1% in morning trading to 1,837p.

The group said: “We have positive momentum on waste, particularly on internal and external sewer flooding, category three pollutions and serious pollution incidents.

“On water, we have had more supply interruptions than normal in the last quarter, but are encouraged by the reduction in water quality complaints, which were down 12% year on year.

“We confirm that we expect to earn at least £50 million customer outperformance payments across waste and water this year.”